as in treacherous
formal
causing harm in a way that is gradual or not easily noticed
Most people with this insidious disease have no idea that they are infected. an insidious enemy
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Recent Examples of insidious
But the kind of harassment that may not rise to the level of a crime in most countries – more pervasive and more subtle, but nonetheless insidious – has largely remained unacknowledged in Brazilian jiu-jitsu.
—
Ina Seethaler, The Conversation, 4 Mar. 2026
Moderate beauty, yet insidious.
—Literary Hub, 2 Mar. 2026
Now there is a new and arguably more insidious form of theatricality to be overcome, a greater threat to the illusionism that lies at the heart of Bove’s bent and colored steel sculptures.
—Gordon Hughes, Artforum, 1 Mar. 2026
But the insidious tentacles of tanking will impact the Heat – and the other Eastern Conference playoff teams – over the final six weeks of the season.
—Barry Jackson, Miami Herald, 26 Feb. 2026
See All Example Sentences for insidious
Ina Seethaler, The Conversation, 4 Mar. 2026
Moderate beauty, yet insidious.
—Literary Hub, 2 Mar. 2026
Now there is a new and arguably more insidious form of theatricality to be overcome, a greater threat to the illusionism that lies at the heart of Bove’s bent and colored steel sculptures.
—Gordon Hughes, Artforum, 1 Mar. 2026
But the insidious tentacles of tanking will impact the Heat – and the other Eastern Conference playoff teams – over the final six weeks of the season.
—Barry Jackson, Miami Herald, 26 Feb. 2026
See All Example Sentences for insidious
Recent Examples of Synonyms for insidious
Adjective
-
Here, a plane crash in treacherous waters leads to survivors fending off sharks.—
Randy Myers,
Mercury News,
18 Mar. 2026
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Rescuers said the conditions were treacherous, with deep drifting snow, jagged ice and extremely limited visibility that slowed efforts to reach the man.—
Ashley Carnahan,
FOXNews.com,
18 Mar. 2026
Adjective
-
Interestingly, the wristband could accurately predict a wide array of hand positions, from 26 letters of complex American Sign Language signs to the subtle grips required for holding scissors, a tennis ball, or a pencil.—
Mrigakshi Dixit,
Interesting Engineering,
25 Mar. 2026
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Mouth breathers tend to carry their head forward to open the airway, a subtle shift that can become its own habitual pattern.—
Allison Palmer,
Miami Herald,
25 Mar. 2026
Adjective
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The problem is that such inferences are often wildly speculative and will almost certainly lead to false convictions or arrests.—
Graham Hillard,
The Washington Examiner,
20 Mar. 2026
-
The defendants and company executives allegedly prepared false documents and communications to show that the company was the end user of the servers.—
Michael Sinkewicz,
FOXNews.com,
20 Mar. 2026
Adjective
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On March 24, the jury found that Meta had violated the state’s consumer protection law by knowingly engaging in an unfair or deceptive trade practice.—
Diana Novak Jones,
USA Today,
25 Mar. 2026
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Admittedly, Palace’s results had been rather deceptive.—
Matt Woosnam,
New York Times,
25 Mar. 2026
Adjective
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The government took a genuine invitation to collaborate as a perfidious power grab.—
Gideon Lewis-Kraus,
New Yorker,
14 Mar. 2026
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For those trying to read Iran’s future, the lesson of 1953 is not just that foreign powers can be perfidious.—
Bobby Ghosh,
Time,
5 Mar. 2026
Adjective
-
The unpredictability of campaigns means that conventional wisdom about frontrunners and inevitability frequently proves incorrect.—
Los Angeles Times,
Los Angeles Times,
25 Mar. 2026
-
Kansas men’s basketball coach Bill Self told The Star on Wednesday morning that internet reports of an imminent retirement announcement are incorrect.—
Gary Bedore,
Kansas City Star,
25 Mar. 2026
Adjective
-
As another election approaches, millions of Floridians can prove just how wrong DeSantis was.—
Steve Bousquet,
Sun Sentinel,
21 Mar. 2026
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On isolated occasions a carp has been spotted on the wrong side of the electrical barrier.—
Dinah Voyles Pulver,
USA Today,
21 Mar. 2026
Cite this Entry
“Insidious.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/insidious. Accessed 26 Mar. 2026.
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